[Cocos2d-x]节点的尺寸大小

作为一个CCNode,本身没有大小而言，但是AddChild之后，便有了尺寸的概念。

Cocos2d-x中对于一个节点的尺寸可以通过以下三个方法获取:

CCSprite:

getContentSize();

获取精灵的逻辑尺寸。此值不受缩放变换影响。即setScale()方法不影响此值

boundingBox().size;

获取精灵的边框尺寸。此值受到缩放变换影响。

getTexture()->getContentSizeInPixels();

获取精灵的纹理的像素尺寸。

像素点和逻辑点关系：逻辑点大小 = 像素大小/contentScale

Ex:

    CCSize sizeByContentSize = pBackground->getContentSize();
    CCSize sizeByboundingBox = pBackground->boundingBox().size;
    CCSize sizeByPoints = pBackground->getTexture()->getContentSizeInPixels();

    CCLOG("sizeByContentSize:width:%f height:%f",sizeByContentSize.width,sizeByContentSize.height);
    CCLOG("sizeByboundingBox:width:%f height:%f",sizeByboundingBox.width,sizeByboundingBox.height);
    CCLOG("sizeByPoints:width:%f height:%f",sizeByPoints.width,sizeByPoints.height);

    pBackground->setScale(2);
    CCLOG("转变后:");

    sizeByContentSize = pBackground->getContentSize();
    sizeByboundingBox = pBackground->boundingBox().size;
    sizeByPoints =pBackground->getTexture()->getContentSizeInPixels();

    CCLOG("sizeByContentSize:width:%f height:%f",sizeByContentSize.width,sizeByContentSize.height);
    CCLOG("sizeByboundingBox:width:%f height:%f",sizeByboundingBox.width,sizeByboundingBox.height);
    CCLOG("sizeByPoints:width:%f height:%f",sizeByPoints.width,sizeByPoints.height);

输出结果:

Cocos2d: sizeByContentSize:width:114.000000 height:114.000000

Cocos2d: sizeByboundingBox:width:114.000000 height:114.000000

Cocos2d: sizeByPoints:width:114.000000 height:114.000000

Cocos2d: 转变后:

Cocos2d: sizeByContentSize:width:114.000000 height:114.000000

Cocos2d: sizeByboundingBox:width:228.000000 height:228.000000

Cocos2d: sizeByPoints:width:114.000000 height:114.000000